var Point = (function () {
  function Point(x, y, time) {
    this.x = x;
    this.y = y;
    this.time = time || Date.now();
  }
  Point.prototype.distanceTo = function (start) {
    return Math.sqrt(Math.pow(this.x - start.x, 2) + Math.pow(this.y - start.y, 2));
  };
  Point.prototype.equals = function (other) {
    return this.x === other.x && this.y === other.y && this.time === other.time;
  };
  Point.prototype.velocityFrom = function (start) {
    return (this.time !== start.time) ? this.distanceTo(start) / (this.time - start.time) : 0;
  };
  return Point;
}());

var Bezier = (function () {
  function Bezier(startPoint, control2, control1, endPoint, startWidth, endWidth) {
    this.startPoint = startPoint;
    this.control2 = control2;
    this.control1 = control1;
    this.endPoint = endPoint;
    this.startWidth = startWidth;
    this.endWidth = endWidth;
  }
  Bezier.fromPoints = function (points, widths) {
    var c2 = this.calculateControlPoints(points[0], points[1], points[2]).c2;
    var c3 = this.calculateControlPoints(points[1], points[2], points[3]).c1;
    return new Bezier(points[1], c2, c3, points[2], widths.start, widths.end);
  };
  Bezier.calculateControlPoints = function (s1, s2, s3) {
    var dx1 = s1.x - s2.x;
    var dy1 = s1.y - s2.y;
    var dx2 = s2.x - s3.x;
    var dy2 = s2.y - s3.y;
    var m1 = { x: (s1.x + s2.x) / 2.0, y: (s1.y + s2.y) / 2.0 };
    var m2 = { x: (s2.x + s3.x) / 2.0, y: (s2.y + s3.y) / 2.0 };
    var l1 = Math.sqrt((dx1 * dx1) + (dy1 * dy1));
    var l2 = Math.sqrt((dx2 * dx2) + (dy2 * dy2));
    var dxm = (m1.x - m2.x);
    var dym = (m1.y - m2.y);
    var k = l2 / (l1 + l2);
    var cm = { x: m2.x + (dxm * k), y: m2.y + (dym * k) };
    var tx = s2.x - cm.x;
    var ty = s2.y - cm.y;
    return {
      c1: new Point(m1.x + tx, m1.y + ty, 0),
      c2: new Point(m2.x + tx, m2.y + ty, 0)
    };
  };
  Bezier.prototype.length = function () {
    var steps = 10;
    var length = 0;
    var px;
    var py;
    for (var i = 0; i <= steps; i += 1) {
      var t = i / steps;
      var cx = this.point(t, this.startPoint.x, this.control1.x, this.control2.x, this.endPoint.x);
      var cy = this.point(t, this.startPoint.y, this.control1.y, this.control2.y, this.endPoint.y);
      if (i > 0) {
        var xdiff = cx - px;
        var ydiff = cy - py;
        length += Math.sqrt((xdiff * xdiff) + (ydiff * ydiff));
      }
      px = cx;
      py = cy;
    }
    return length;
  };
  Bezier.prototype.point = function (t, start, c1, c2, end) {
    return (start * (1.0 - t) * (1.0 - t) * (1.0 - t))
      + (3.0 * c1 * (1.0 - t) * (1.0 - t) * t)
      + (3.0 * c2 * (1.0 - t) * t * t)
      + (end * t * t * t);
  };
  return Bezier;
}());

function throttle(fn, wait) {
  if (wait === void 0) { wait = 250; }
  var previous = 0;
  var timeout = null;
  var result;
  var storedContext;
  var storedArgs;
  var later = function () {
    previous = Date.now();
    timeout = null;
    result = fn.apply(storedContext, storedArgs);
    if (!timeout) {
      storedContext = null;
      storedArgs = [];
    }
  };
  return function () {
    var args = [];
    for (var _i = 0; _i < arguments.length; _i++) {
      args[_i] = arguments[_i];
    }
    var now = Date.now();
    var remaining = wait - (now - previous);
    storedContext = this;
    storedArgs = args;
    if (remaining <= 0 || remaining > wait) {
      if (timeout) {
        clearTimeout(timeout);
        timeout = null;
      }
      previous = now;
      result = fn.apply(storedContext, storedArgs);
      if (!timeout) {
        storedContext = null;
        storedArgs = [];
      }
    }
    else if (!timeout) {
      timeout = window.setTimeout(later, remaining);
    }
    return result;
  };
}

var SignaturePad = (function () {
  function SignaturePad(canvas, options) {
    if (options === void 0) { options = {}; }
    var _this = this;
    this.canvas = canvas;
    this.options = options;
    this._handleMouseDown = function (event) {
      if (event.which === 1) {
        _this._mouseButtonDown = true;
        _this._strokeBegin(event);
      }
    };
    this._handleMouseMove = function (event) {
      if (_this._mouseButtonDown) {
        _this._strokeMoveUpdate(event);
      }
    };
    this._handleMouseUp = function (event) {
      if (event.which === 1 && _this._mouseButtonDown) {
        _this._mouseButtonDown = false;
        _this._strokeEnd(event);
      }
    };
    this._handleTouchStart = function (event) {
      event.preventDefault();
      if (event.targetTouches.length === 1) {
        var touch = event.changedTouches[0];
        _this._strokeBegin(touch);
      }
    };
    this._handleTouchMove = function (event) {
      event.preventDefault();
      var touch = event.targetTouches[0];
      _this._strokeMoveUpdate(touch);
    };
    this._handleTouchEnd = function (event) {
      var wasCanvasTouched = event.target === _this.canvas;
      if (wasCanvasTouched) {
        event.preventDefault();
        var touch = event.changedTouches[0];
        _this._strokeEnd(touch);
      }
    };
    this.velocityFilterWeight = options.velocityFilterWeight || 0.7;
    this.minWidth = options.minWidth || 0.5;
    this.maxWidth = options.maxWidth || 2.5;
    this.throttle = ('throttle' in options ? options.throttle : 16);
    this.minDistance = ('minDistance' in options ? options.minDistance : 5);
    if (this.throttle) {
      this._strokeMoveUpdate = throttle(SignaturePad.prototype._strokeUpdate, this.throttle);
    }
    else {
      this._strokeMoveUpdate = SignaturePad.prototype._strokeUpdate;
    }
    this.dotSize = options.dotSize || function () {
      return (this.minWidth + this.maxWidth) / 2;
    };
    this.penColor = options.penColor || 'black';
    this.backgroundColor = options.backgroundColor || 'rgba(0,0,0,0)';
    this.onBegin = options.onBegin;
    this.onEnd = options.onEnd;
    this._ctx = canvas.getContext('2d');
    this.clear();
    this.on();
  }
  SignaturePad.prototype.clear = function () {
    var ctx = this._ctx;
    var canvas = this.canvas;
    ctx.fillStyle = this.backgroundColor;
    ctx.clearRect(0, 0, canvas.width, canvas.height);
    ctx.fillRect(0, 0, canvas.width, canvas.height);
    this._data = [];
    this._reset();
    this._isEmpty = true;
  };
  SignaturePad.prototype.fromDataURL = function (dataUrl, options, callback) {
    var _this = this;
    if (options === void 0) { options = {}; }
    var image = new Image();
    var ratio = options.ratio || window.devicePixelRatio || 1;
    var width = options.width || (this.canvas.width / ratio);
    var height = options.height || (this.canvas.height / ratio);
    this._reset();
    image.onload = function () {
      _this._ctx.drawImage(image, 0, 0, width, height);
      if (callback) {
        callback();
      }
    };
    image.onerror = function (error) {
      if (callback) {
        callback(error);
      }
    };
    image.src = dataUrl;
    this._isEmpty = false;
  };
  SignaturePad.prototype.toDataURL = function (type, encoderOptions) {
    if (type === void 0) { type = 'image/png'; }
    switch (type) {
      case 'image/svg+xml':
        return this._toSVG();
      default:
        return this.canvas.toDataURL(type, encoderOptions);
    }
  };
  SignaturePad.prototype.on = function () {
    this.canvas.style.touchAction = 'none';
    this.canvas.style.msTouchAction = 'none';
    if (window.PointerEvent) {
      this._handlePointerEvents();
    }
    else {
      this._handleMouseEvents();
      if ('ontouchstart' in window) {
        this._handleTouchEvents();
      }
    }
  };
  SignaturePad.prototype.off = function () {
    this.canvas.style.touchAction = 'auto';
    this.canvas.style.msTouchAction = 'auto';
    this.canvas.removeEventListener('pointerdown', this._handleMouseDown);
    this.canvas.removeEventListener('pointermove', this._handleMouseMove);
    document.removeEventListener('pointerup', this._handleMouseUp);
    this.canvas.removeEventListener('mousedown', this._handleMouseDown);
    this.canvas.removeEventListener('mousemove', this._handleMouseMove);
    document.removeEventListener('mouseup', this._handleMouseUp);
    this.canvas.removeEventListener('touchstart', this._handleTouchStart);
    this.canvas.removeEventListener('touchmove', this._handleTouchMove);
    this.canvas.removeEventListener('touchend', this._handleTouchEnd);
  };
  SignaturePad.prototype.isEmpty = function () {
    return this._isEmpty;
  };
  SignaturePad.prototype.fromData = function (pointGroups) {
    var _this = this;
    this.clear();
    this._fromData(pointGroups, function (_a) {
      var color = _a.color, curve = _a.curve;
      return _this._drawCurve({ color: color, curve: curve });
    }, function (_a) {
      var color = _a.color, point = _a.point;
      return _this._drawDot({ color: color, point: point });
    });
    this._data = pointGroups;
  };
  SignaturePad.prototype.toData = function () {
    return this._data;
  };
  SignaturePad.prototype._strokeBegin = function (event) {
    var newPointGroup = {
      color: this.penColor,
      points: []
    };
    this._data.push(newPointGroup);
    this._reset();
    this._strokeUpdate(event);
    if (typeof this.onBegin === 'function') {
      this.onBegin(event);
    }
  };
  SignaturePad.prototype._strokeUpdate = function (event) {
    var x = event.clientX;
    var y = event.clientY;
    var point = this._createPoint(x, y);
    var lastPointGroup = this._data[this._data.length - 1];
    var lastPoints = lastPointGroup.points;
    var lastPoint = lastPoints.length > 0 && lastPoints[lastPoints.length - 1];
    var isLastPointTooClose = lastPoint ? point.distanceTo(lastPoint) <= this.minDistance : false;
    var color = lastPointGroup.color;
    if (!lastPoint || !(lastPoint && isLastPointTooClose)) {
      var curve = this._addPoint(point);
      if (!lastPoint) {
        this._drawDot({ color: color, point: point });
      }
      else if (curve) {
        this._drawCurve({ color: color, curve: curve });
      }
      lastPoints.push({
        time: point.time,
        x: point.x,
        y: point.y
      });
    }
  };
  SignaturePad.prototype._strokeEnd = function (event) {
    this._strokeUpdate(event);
    if (typeof this.onEnd === 'function') {
      this.onEnd(event);
    }
  };
  SignaturePad.prototype._handlePointerEvents = function () {
    this._mouseButtonDown = false;
    this.canvas.addEventListener('pointerdown', this._handleMouseDown);
    this.canvas.addEventListener('pointermove', this._handleMouseMove);
    document.addEventListener('pointerup', this._handleMouseUp);
  };
  SignaturePad.prototype._handleMouseEvents = function () {
    this._mouseButtonDown = false;
    this.canvas.addEventListener('mousedown', this._handleMouseDown);
    this.canvas.addEventListener('mousemove', this._handleMouseMove);
    document.addEventListener('mouseup', this._handleMouseUp);
  };
  SignaturePad.prototype._handleTouchEvents = function () {
    this.canvas.addEventListener('touchstart', this._handleTouchStart);
    this.canvas.addEventListener('touchmove', this._handleTouchMove);
    this.canvas.addEventListener('touchend', this._handleTouchEnd);
  };
  SignaturePad.prototype._reset = function () {
    this._lastPoints = [];
    this._lastVelocity = 0;
    this._lastWidth = (this.minWidth + this.maxWidth) / 2;
    this._ctx.fillStyle = this.penColor;
  };
  SignaturePad.prototype._createPoint = function (x, y) {
    var rect = this.canvas.getBoundingClientRect();
    return new Point(x - rect.left, y - rect.top, new Date().getTime());
  };
  SignaturePad.prototype._addPoint = function (point) {
    var _lastPoints = this._lastPoints;
    _lastPoints.push(point);
    if (_lastPoints.length > 2) {
      if (_lastPoints.length === 3) {
        _lastPoints.unshift(_lastPoints[0]);
      }
      var widths = this._calculateCurveWidths(_lastPoints[1], _lastPoints[2]);
      var curve = Bezier.fromPoints(_lastPoints, widths);
      _lastPoints.shift();
      return curve;
    }
    return null;
  };
  SignaturePad.prototype._calculateCurveWidths = function (startPoint, endPoint) {
    var velocity = (this.velocityFilterWeight * endPoint.velocityFrom(startPoint))
      + ((1 - this.velocityFilterWeight) * this._lastVelocity);
    var newWidth = this._strokeWidth(velocity);
    var widths = {
      end: newWidth,
      start: this._lastWidth
    };
    this._lastVelocity = velocity;
    this._lastWidth = newWidth;
    return widths;
  };
  SignaturePad.prototype._strokeWidth = function (velocity) {
    return Math.max(this.maxWidth / (velocity + 1), this.minWidth);
  };
  SignaturePad.prototype._drawCurveSegment = function (x, y, width) {
    var ctx = this._ctx;
    ctx.moveTo(x, y);
    ctx.arc(x, y, width, 0, 2 * Math.PI, false);
    this._isEmpty = false;
  };
  SignaturePad.prototype._drawCurve = function (_a) {
    var color = _a.color, curve = _a.curve;
    var ctx = this._ctx;
    var widthDelta = curve.endWidth - curve.startWidth;
    var drawSteps = Math.floor(curve.length()) * 2;
    ctx.beginPath();
    ctx.fillStyle = color;
    for (var i = 0; i < drawSteps; i += 1) {
      var t = i / drawSteps;
      var tt = t * t;
      var ttt = tt * t;
      var u = 1 - t;
      var uu = u * u;
      var uuu = uu * u;
      var x = uuu * curve.startPoint.x;
      x += 3 * uu * t * curve.control1.x;
      x += 3 * u * tt * curve.control2.x;
      x += ttt * curve.endPoint.x;
      var y = uuu * curve.startPoint.y;
      y += 3 * uu * t * curve.control1.y;
      y += 3 * u * tt * curve.control2.y;
      y += ttt * curve.endPoint.y;
      var width = curve.startWidth + (ttt * widthDelta);
      this._drawCurveSegment(x, y, width);
    }
    ctx.closePath();
    ctx.fill();
  };
  SignaturePad.prototype._drawDot = function (_a) {
    var color = _a.color, point = _a.point;
    var ctx = this._ctx;
    var width = typeof this.dotSize === 'function' ? this.dotSize() : this.dotSize;
    ctx.beginPath();
    this._drawCurveSegment(point.x, point.y, width);
    ctx.closePath();
    ctx.fillStyle = color;
    ctx.fill();
  };
  SignaturePad.prototype._fromData = function (pointGroups, drawCurve, drawDot) {
    for (var _i = 0, pointGroups_1 = pointGroups; _i < pointGroups_1.length; _i++) {
      var group = pointGroups_1[_i];
      var color = group.color, points = group.points;
      if (points.length > 1) {
        for (var j = 0; j < points.length; j += 1) {
          var basicPoint = points[j];
          var point = new Point(basicPoint.x, basicPoint.y, basicPoint.time);
          this.penColor = color;
          if (j === 0) {
            this._reset();
          }
          var curve = this._addPoint(point);
          if (curve) {
            drawCurve({ color: color, curve: curve });
          }
        }
      }
      else {
        this._reset();
        drawDot({
          color: color,
          point: points[0]
        });
      }
    }
  };
  SignaturePad.prototype._toSVG = function () {
    var _this = this;
    var pointGroups = this._data;
    var ratio = Math.max(window.devicePixelRatio || 1, 1);
    var minX = 0;
    var minY = 0;
    var maxX = this.canvas.width / ratio;
    var maxY = this.canvas.height / ratio;
    var svg = document.createElementNS('http://www.w3.org/2000/svg', 'svg');
    svg.setAttribute('width', this.canvas.width.toString());
    svg.setAttribute('height', this.canvas.height.toString());
    this._fromData(pointGroups, function (_a) {
      var color = _a.color, curve = _a.curve;
      var path = document.createElement('path');
      if (!isNaN(curve.control1.x) &&
        !isNaN(curve.control1.y) &&
        !isNaN(curve.control2.x) &&
        !isNaN(curve.control2.y)) {
        var attr = "M " + curve.startPoint.x.toFixed(3) + "," + curve.startPoint.y.toFixed(3) + " "
          + ("C " + curve.control1.x.toFixed(3) + "," + curve.control1.y.toFixed(3) + " ")
          + (curve.control2.x.toFixed(3) + "," + curve.control2.y.toFixed(3) + " ")
          + (curve.endPoint.x.toFixed(3) + "," + curve.endPoint.y.toFixed(3));
        path.setAttribute('d', attr);
        path.setAttribute('stroke-width', (curve.endWidth * 2.25).toFixed(3));
        path.setAttribute('stroke', color);
        path.setAttribute('fill', 'none');
        path.setAttribute('stroke-linecap', 'round');
        svg.appendChild(path);
      }
    }, function (_a) {
      var color = _a.color, point = _a.point;
      var circle = document.createElement('circle');
      var dotSize = typeof _this.dotSize === 'function' ? _this.dotSize() : _this.dotSize;
      circle.setAttribute('r', dotSize.toString());
      circle.setAttribute('cx', point.x.toString());
      circle.setAttribute('cy', point.y.toString());
      circle.setAttribute('fill', color);
      svg.appendChild(circle);
    });
    var prefix = 'data:image/svg+xml;base64,';
    var header = '<svg'
      + ' xmlns="http://www.w3.org/2000/svg"'
      + ' xmlns:xlink="http://www.w3.org/1999/xlink"'
      + (" viewBox=\"" + minX + " " + minY + " " + maxX + " " + maxY + "\"")
      + (" width=\"" + maxX + "\"")
      + (" height=\"" + maxY + "\"")
      + '>';
    var body = svg.innerHTML;
    if (body === undefined) {
      var dummy = document.createElement('dummy');
      var nodes = svg.childNodes;
      dummy.innerHTML = '';
      for (var i = 0; i < nodes.length; i += 1) {
        dummy.appendChild(nodes[i].cloneNode(true));
      }
      body = dummy.innerHTML;
    }
    var footer = '</svg>';
    var data = header + body + footer;
    return prefix + btoa(data);
  };
  return SignaturePad;
}());

export default SignaturePad;